Treatment response of neurological soft signs in drug-naïve patients with a first psychotic episode

Abstract Background Neurological soft signs (NSS) are intrinsic features of psychosis that appear years before beginning a drug treatment. However, whether NSS respond to antipsychotics and whether these changes are clinically reliable and significant remains to be seen. Objective We sought to determine the effect of antipsychotics on NSS in a first-episode psychosis (FEP) sample who had never exposed to antipsychotics. Methods We included 100 antipsychotic-naïve patients with FEP in this study. 77 patients completed the study assessments at baseline, 1 month and 6 months. The Neurological Evaluation Scale (NES) evaluated NSS. Patients were alternatively selected to receive risperidone or olanzapine treatments and continued participation in their mental health setting during follow-up with one of four treatment groups: risperidone, olanzapine, mixed antipsychotics or no medication. We also included a control group of 28 healthy volunteers. Results Treatment groups showed a statistically significant improvement on total NES scores and most NES subscales except for ‘frontal signs’, regardless of antipsychotic allocation. NSS changes were reliable; however, there was great variation in the total NES scores between treatment groups, ranging from 4% to 24%. Clinically meaningful changes (CMCs) on total NES scores ranged from 25% to 50%. Six patients (7.8%) demonstrated a reliable change (RC) and CMC on total NES scores. Conclusions NSS improved significantly over follow up regardless of the treatment regimen assigned to antipsychotic-naïve patients with a FEP. However, only 6 (7.8%) achieved a reliable and clinically meaningful improvement. The pattern of response of NSS to antipsychotic drugs evidenced both state and trait characteristics.